Sorry for bad English.
To generate JWT-token i'm using
jwt = require('jsonwebtoken');
/* some code */
//function to create jwt-token
function createToken(user) {
return jwt.sign(user, config.secret, { expiresIn: 60*60*5 });
}
/* some code */
//after registration/authorization (if success) createToken token function is calling
createToken(user);
I would like to learn the best practices, what data must be passed to a function to create the token.
For example, can this be as:
login (John) and id( ObjectId("5821d94dbb021a1360582da3") when using MongoDb)?
And here, I think, will be relevant question:
If I store in token some information that allows initialize user, I can pull its data from the database. Is this correct, initialize the user from authorization header from JWT? For initialization I'm using express-jwt, which, if successful, sets req.user?
Thanks.
you can put the generated token in browser local storage, if you are using browser. You can also store session values in the token itself, those values will be decoded on the server side by nodejs.
Related
I'm working on an Ionic application.
On the one hand I have an auth basic form in which people fill in their username and password. On the other hand I'd like to implement authentification with JSON Web Tokens and Node JS.
The workflow would be this one : as soon as a user fills in his credentials, they will be sent with a POST request. If these credentials are correct, the user can access to the application and gets an access token as a response.
The thing is that I'm a little bit lost with all that concepts. I built a form and sent informations with a POST request. I managed to create some APIs with Node JS and that's ok. I see how to build a authentified webservice too (e.g : https://github.com/jkasun/stack-abuse-express-jwt/blob/master/auth.js).
But I concretely don't understand the links between the html form and the authorisation check part..
To be clearer, how is it possible to make the html part and the Node JS scripts communicate together ?
Before posting that question I made many researches and found many stuff on building an authentified API. But there was very few advice on how to make it communicate with the client part (I mean the form), which is what I have to do.
If anyone has any ressources (document, Github examples..) on that, I'll greatly appreciate. But I would be very happy too if someone try to make me understand these concepts. I guess I have to improve my knowledge on all that so that I could test some POCs.
Many thanks in advance !
JWT General flow:
1- Authenticate using a strategy (You done it)
2- Deliver an accessToken along with response (You done it)
3- The client MUST store this accessToken (LocalStorage is the best place, not cookies: They are vulnerable to csrf attacks)
4- On every request you are going to make to a protected area (where user is supposed to be authenticated and authorized), make sure to send you accessToken along with it, you can put it on Authorization header, a custom header, directly in body of the request... Basicaly just make sure to send it properly.
5- On the server receiving client requests, you NEED to verify that token (You verify it by checking the signature of the accessToken).
6- If he is authorized, great, if not, send back an HTTP Unauthorized Error.
Here is my implementation using an accessToken on a header + passportjs-jwt:
Client code
To store token:
localStorage.setItem('accessToken', myAccessToken);
To send it:
const myAccessToken = localStorage.getItem('accessToken');
{
headers: {'Authorization', `Bearer ${myAccessToken}`}
}
Server code
1- Configure passport
passport.use('jwt', new JwtStrategy({
jwtFromRequest: jwtPassport.ExtractJwt.fromAuthHeaderAsBearerToken(),
secretOrKey: myAccessTokenSecret,
passReqToCallback: true
}, (req, payload, done: (err?, user?) => void): void {
User
.findOne({where: {id: req.params.id}})
.then((user: User) => {
if (!user) {
return done(new Error(`No user found with id: ${req.params.id}`), null);
}
return done(null, user);
})
.catch((e: Error) => done(e, null));
}));
Pay attention to callback: If your callback is called, it means that passport has successfuly verified the token (It is valid). In my example, i get the user details in database and this is the user that will be returned and put in req.user object passed to my controller below:
2- Finally, the controller route (protected area):
.get('/users/:id', passport.authenticate('jwt'), (req, res, next) => {
// do stuff in protected area.
}
And that's it. If you want more security, check refreshTokens implementation.
I used passport because i found it relevant in my case, but you can write your own handler, by using jsonwebtoken and just calling its "verify" function.
You can find documentation of passport jwt strategy here => http://www.passportjs.org/packages/passport-jwt/
I am new to Next.js and I am struggling with the authentication system using jwt token. I want to know what is the best / standard way to store the jwt token and routing with the authentication system. I have been trying different approaches, from different tutorials/articles, but do not quite understand it. Here are what I have tried.
When the user login, it sends username/password to a separated API server (ex. new project that handles backend stuff), the server will respond with the access-token, then in Next.js project, I set the cookie with that received token. In Next.js project, protected routes will be wrapped with a withAuth hoc, which will check for the token in a cookie. The problem with this approach is that it is vulnerable to XSS because the cookie has no httpOnly flag.
This is similar to 1.) but using localStorage, the problem is access-token could not be sent to the server on the first request. (This one I'm not sure, but in my understanding, in every HTTP request, I must stick my access-token manually, so what about requests that I have no control over? ex. first request or using <a> tag).
I wrote authentication backend inside Next.js server (custom express server). When the user login, the server will validate it and then set an httpOnly cookie. Then the problem is, with client-side routing (go to URL using Next.js Router), it could not check for token. For example, if a page is wrapped with withAuth hoc, but it cannot access the token inside cookies with javascript.
And I've seen a lot of people, in getInitialProps of the protected route, they only check for existence token in cookie / localStorage, then what if the token is being revoked or blacklisted, how do they handle it because they did not send the token to the server? Or do I have to send the token to the server in every client-side page change?
Since we are on quarantine I have enough time to answer this question. It will be a long answer.
Next.js uses the App component to initialize the pages. _app page is responsible for rendering our pages. We authenticate users on _app.js because anything that we return from getInitialProps can be accessed by all of the other pages. We authenticate user here, authentication decision will be passed to pages, from pages to header, so each page can decide if the user is authenticated or not. (Note that it could be done with redux without prop drilling but it would make the answer more complex)
static async getInitialProps({ Component, router, ctx }) {
let pageProps = {};
const user = process.browser
? await auth0.clientAuth()
: await auth0.serverAuth(ctx.req); // I explain down below
//this will be sent to all the components
const auth = { user, isAuthenticated: !!user };
if (Component.getInitialProps) {
pageProps = await Component.getInitialProps(ctx);
}
return { pageProps, auth };
}
render() {
const { Component, pageProps, auth } = this.props;
return <Component {...pageProps} auth={auth} />;
}
}
If we are on the browser and need to check if a user is authenticated, we just retrieve the cookie from the browser, which is easy. But we always have to verify the token. It is the same process used by browser and server. I will explain down below. But if we are on the server. we have no access to the cookies in the browser. But we can read from the "req" object because cookies are attached to the req.header.cookie. this is how we access to cookies on the server.
async serverAuth(req) {
// console.log(req.headers.cookie) to check
if (req.headers.cookie) {
const token = getCookieFromReq(req, "jwt");
const verifiedToken = await this.verifyToken(token);
return verifiedToken;
}
return undefined;
}
here is getCookieFromReq(). remember we have to think functional.
const getCookieFromReq = (req, cookieKey) => {
const cookie = req.headers.cookie
.split(";")
.find((c) => c.trim().startsWith(`${cookieKey}=`));
if (!cookie) return undefined;
return cookie.split("=")[1];
};
Once we get the cookie, we have to decode it, extract the expiration time to see if it is valid or not. this part is easy. Another thing we have to check is if the signature of the jwt is valid. Symmetric or asymmetric algorithms are used to sign the jwt. You have to use private keys to validate the signature of symmetric algorithms. RS256 is the default asymmetric algorithms for APIs. Servers that use RS256, provide you with a link to get jwt to use the keys to validate the signature. You can either use [jwks-rsa][1] or you can do on your own. You have to create a certificate and then verify if the token is valid.
Assume that our user authenticated now. You said, "And I've seen a lot of people, in getInitialProps of the protected route, they only check for existence token in cookie / localStorage,". We use protected routes to give access only to the authorized users. In order to access those routes, users have to show their jwt tokens and express.js uses middlewares to check if the user's token is valid. Since you have seen a lot of examples, I will skip this part.
"then what if the token is being revoked or blacklisted, how do they handle it because they did not send the token to the server? Or do I have to send the token to a server in every client-side page changing?"
with verifying token process we are 100% sure if the token is valid or not. When a client asks the server to access some secret data, the client has to send the token to the server. Imagine when you mount the component, component asks the server to get some data from the protected routes. The server will extract the req object, take the jwt and use it to fetch data from the protected routes. Implementation of the fetching data for browser and server are different. And if the browser makes a request, it just needs the relative path but the server needs an absolute path. As you should know fetching data is done getInitialProps() of the component and this function executed on both client and server. here is how you should implement it. I just attached the getInitialProps() part.
MyComponent.getInitialProps = async (ctx) => {
const another = await getSecretData(ctx.req);
//reuslt of fetching data is passed to component as props
return { superValue: another };
};
const getCookieFromReq = (req, cookieKey) => {
const cookie = req.headers.cookie
.split(";")
.find((c) => c.trim().startsWith(`${cookieKey}=`));
if (!cookie) return undefined;
return cookie.split("=")[1];
};
const setAuthHeader = (req) => {
const token = req ? getCookieFromReq(req, "jwt") : Cookies.getJSON("jwt");
if (token) {
return {
headers: { authorization: `Bearer ${token}` },
};
}
return undefined;
};
export const getSecretData = async (req) => {
const url = req ? "http://localhost:3000/api/v1/secret" : "/api/v1/secret";
return await axios.get(url, setAuthHeader(req)).then((res) => res.data);
};
[1]: https://www.npmjs.com/package/jwks-rsa
With the introduction of Next.JS v8, there are examples placed in the NextJS example page. The basic idea to follow is:
JWT
Using cookies to store the token (you may choose to further encrypt it or not)
Sending the cookies as authorization headers
OAuth
Using a third-party authentication service such as OAuth2.0
Using Passport
This question might need an updated answer, now middlewares are there in Next.js 12 (october 2021): https://nextjs.org/docs/middleware
I am drafting a comprehensive answer to explain auth in Next.js more deeply, you can follow the progress there on GitHub
Here I'll try to propose a summary for Next.js, using middlewares.
Verifying the token after auth and redirecting accordingly
Most of the answer from #Yilmaz from april 2020 is still relevant. However, previously, we had to use getInitialProps in _app to process the request OR a custom server.
This is no longer the case.. Using a middleware let's you achieve a similar purpose, with cleaner code. Because middleware are specifically designed for such use cases.
Here, I suppose you get a JWT access token using an asymetrical algorithm like RS256, exactly like in this previous answer.
Here is a possible implementation:
import { NextFetchEvent, NextRequest, NextResponse } from "next/server";
const removeCookie = (res: NextResponse, cookieName: string) => {
res.headers.append("Set-Cookie", `${cookieName}=; Max-Age=-1; Path=/`);
return res;
};
export default async function middleware(
req: NextRequest,
ev: NextFetchEvent
) {
const { pathname } = req.nextUrl;
const isPublic = isPublicRoute(pathname);
if (isPublic) {
return NextResponse.next();
}
const accessToken = req.cookies[TOKEN_PATH];
if (!accessToken) {
return NextResponse.redirect(LOGIN_HREF);
}
const isValidToken = await checkAccessToken(accessToken);
if (!isValidToken) {
let res = NextResponse.redirect(LOGIN_HREF);
res = removeCookie(res, TOKEN_PATH);
return res;
}
return NextResponse.next();
}
How to verify the token
In my example, the checkAccessToken should verify the token (not decode, verify the signature).
This is where things are the most complicated imo.
When using the RSA256 algorithm
You also get a PUBLIC certificate (in addition to the SECRET key that must be... kept secret). Eventhough you do the check in the middleware, which is private and server-only code, that's good news because it means you could even use it in the browser, in theory.
So, you can either fetch the token validation endpoint provided by your auth server, or verify the token yourself.
Fetching is not the recommended option because it might break Vercel/Next edge capabilities and add latency, according to the documentation.
I must admit that I did not succeed to verify the token yet using Next.js :) I'll update this answer if I manage to have a code sample that works.
When using a symmetrical encryption
You have only a PRIVATE secret passphrase. It means that the decoding have to happen server-side (good news, you are writing a middleware).
Login/logout
This doesn't change with middlewares. You store your access token as an httpOnly cookie. When logging out, you unset this cookie.
Managing those Set-Cookies headers are the responsibility of your auth server.
This is a basic workflow but it should work. You can then add a refresh token in the mix with a similar approach.
About token revokation
If you verify the token in your middleware, there is no immediate revokation mechanism for the access token. Because there is no call to a database.
Therefore, in this scenario, you'd want to opt-in for short lived access token (eg 5 minutes) coupled with a refresh token. You can revoke the refresh token, so basically revoking works but takes a few minutes.
If a 3rd party server verifies the token: then it could check for blacklisted tokens.
Caveats
Also, some piece of advice: most articles, tutorials etc. online are focused on server-to-server communication. Or client-to-API. They completely suck when it comes to check authentication before accessing web pages.
For instance, setting the Authorization header is not possible in the browser. It works only when communicating with an API. Cookies are mandatory for web pages.
Even then, if this API is meant to be called from a browser, it should preferably accept a cookie.
When discussing with experts on the field, you need to always clarify the Next.js use case.
Open questions: about session-based authentication
Some frameworks seem to prefer relying on the database. They store a hashed token in the db, which acts as a session. If you want to check auth, you need a server that will check the user's token against the stored token (= checking that there is an active session with this token).
I am thinking of Meteor for instance.
I couldn't find the name of this mechanism and its actual relation to JWT however. Are they simply variations of the JWT approach?
Next.js official authentication doc is not showing middlewares at the time of writing, but instead use getServerSideProps. I really don't like this pattern.
It uses a kind of session system but I am not clear about the internals of it, I am not even sure of the name (is that session-based auth?).
Vercel edge handles examples shows how to secure an API route, but not a page (at the time of writing)
I have created node js app using express framework.
I have created middleware for restricting access to some routes.
Middleware actually works fine. but i have difficulties in displaying data.
Suppose In My app i have created route for display list of countries('/country/master')i.e html page which is using internally different/default route ('/country/') to get data from mongoDB.
In this case user will not able to see data cause i have not given permission to "/" routes. but i want to display data but not allow him to make use of "/" route to check data.
How can i deal with this case ????
The answer depends on your authentication strategy i.e. are you using session identifiers, access tokens, etc.
In either case I suggest that you break out the credential exchange (aka login) from the authentication. They should be separate middleware functions. Below is an example of what this looks like.
While this answers your question, specific to ExpressJS, it does leave out a lot of other details that matter when you are building an authentication system (like how to securely store passwords). I work at Stormpath, we provide user management as an API so that you don't have to worry about all the security details! It's very easy to integrate our API into your application, using the express-stormpath module. You'll have a fully featured user database in minutes, without having to setup mongo or a user table.
All that said, here's the example:
/* pseudo example of building your own authentication middleware */
function usernamePasswordExchange(req,res,next){
var username = req.body.username;
var password = req.body.password;
callToAuthService(username,password,function(err,user){
if(err){
next(err); // bad password, user doesn’t exist, etc
}else{
/*
this part depends on your application. do you use
sessions or access tokens? you need to send the user
something that they can use for authentication on
subsequent requests
*/
res.end(/* send something */);
}
});
}
function authenticate(req,res,next){
/*
read the cookie, access token, etc.
verify that it is legit and then find
the user that it’s associated with
*/
validateRequestAndGetUser(req,function(err,user){
if(err){
next(err); // session expired, tampered, revoked
}else{
req.user = user;
next();
}
});
}
app.post('/login',usernamePasswordExchange);
app.get('/protected-resource',authenticate,function(req,res,next){
/*
If we are here we know the user is authenticated and we
can know who the user is by referencing req.user
*/
});
You can positioning of middleware in you app.for example:-
app.get('/country/master',function(req,res){
})
app.use(function(req,res){
your middle ware for providing authentication
})
// other routes where authentication should be enabled
app.get('other urls')
I have a startup module in angularjs. This module is just to login and have public information (login, prices, newsletter...). I have many roles and for each role, i have an app (angular module). I made this architecture because i have complex module for each role and it was impossible to put all roles in one module.
So, for login, i use jsonwebtoken in node like this :
var token = jwt.sign(user, config.secureToken, { expiresInMinutes: 20*5});
res.json({ token: token, user: user });
It works perfectly. I can login into my app. After that, i have to propose a list of roles to redirect to the right module.
In angular, I have AuthHttp service that adds security headers (with token) to call rest service with $http.
How can i redirect to 'mydomain:port/anotherModule' with $location or $http ?
With this code in nodejs :
app.get('/secondModule', expressJwt({secret: config.secureToken}), function (req, res) {
res.render('restricted/secondModule/index.html');
});
NodeJs sends an html code in response and does'nt redirect...
And if i do this in my angular controller :
location.href = route;
i have this result on nodejs console :
Error: No Authorization header was found
I am not sure about the libraries you are using, but issue seems that you are loosing the token because you navigate to a altogether new page.
Based on your auth library you need to pass the token that you get after auth from one page to another.
The options here are to either use browser sessionStorage or querystring to pass the token along and at it back to the http header collection on the new page (module)
This is an old post but I recently took a long time to figure this out. I may be wrong but I believe nodeJS/expressJS can't read the token from the session storage. I believe you will need to pass the token via the request header using AngularJS.
This depends on the front end that you are using. For me, I am using AngularJS and I have to do something like this.
angular.module('AngularApp').factory('authFactory',
function($window){ //the window object will be able to access the token
var auth = {};
auth.saveToken = function(token){
$window.localStorage['token_name'] = token; //saving the token
}
auth.getToken = function(){
return $window.localStorage['token_name']; //retrieving the token
}
return auth;
}
.service('authInterceptor, function(authFactory){
return { headers: {Authorization: 'Bearer "+ authFactory.getToken()}
} //the last line gets the retrieved token and put it in req.header
Then, you just need to include 'authInterceptor' in all the http methods when you communicate with the backend. This way, nodeJS will be able to pick up the token.
You can see the Authorization field in req.header if you use the chrome developer tool and look at the Network tab. Hope this helps.
I am using a combination of Node.js and Passportjs on the server-side, and Emberjs on the client side for an app. My current Authentication strategy is to use Passport-Local to authenticate users with normal email/password combinations as standard, and then hook in a session creation mechanism to generate an Authentication Token, which is saved into a separate table, and passed back to the user for use in any further protected routes. (passed in the REST header).
Creation of the token is fine, i'm doing that without issue, however i'm struggling to work out if I need an extra step.
Currently, I generate the token with node-jwt-simple by using a random node-uuid pass as the payload, and the users UID (another node-uuid) as the secret. I then save this to a $.cookie on the clientside, and to a table on the serverside, along with a creation date.
Obviously, one of the steps in node-jwt-simple is to encode the token. There is also a decode function provided. My question is, do I need to decode the token into something when I am doing my auth checking, or is simply checking the user's session cookie (REST header) for a match against the token in the database sufficient? I wouldn't want to go to all the effort of having generated a token, only to then miss an important step, but i'm not seeing how I could decode it into anything that would provide any additional useful security.
UPDATE:
I think I worked this out last night:
The solution seems to be to use the User's UID as the payload for JWT, with a static string as the secret (taken from something like a server environment variable or similar), and then only store the encoded token in the database. Pass the token back to the client for re-auth, then when the client attempts to access a protected route, they must pass their UID along with the encoded token to the server, which is then decoded, and the decoded payload compared to the UID that has been passed. If they match, the auth is successful, otherwise the token is destroyed and the user has to log in again.
By doing this, it makes the store of tokens effectively useless without knowing either the Secret key, or having the User's UID, but makes the auth process more secure.
If you don't validate the token, you could as well create some other random data to use as a session cookie, as long as it is unique and cannot be guessed by clients.
But as you already made a lot of effort, you could encode something useful in the token which tells you how long it is valid, e.g. an exp field, so you don't have to read from the database.
I'm not sure if I fully understand your JWT, but the problem I see is that you need information to decode the token which is probably not at your hand. So you have to do a search in your database.
I think it would be sufficient to use some random session key, e.g. following function:
var crypto = require('crypto');
/**
* Create random bytes and encode base64url.
* #param {int} [lengthInBytes=40] the size of the raw token in bytes
* (will be longer since base64url-encoded)
* #param {function} callback node-style callback-function;
* data-parameter is a string w/ a shortened (no trailing ==)
* base64url-encoded string of the generated bytes.
*/
exports.createRandomToken = function createRandomToken(lengthInBytes, callback) {
if (typeof lengthInBytes === 'function') {
callback = lengthInBytes;
lengthInBytes = 40;
}
crypto.randomBytes(lengthInBytes, function (ex, buf) {
if (ex) {
callback(ex);
return;
}
callback(null, buf.toString('base64')
.replace(/\//g, '_')
.replace(/\+/g, '-')
.replace(/=/g, ''));
});
};
Set expire time of the token as small as possible(5 min, 30 min, nor months neither years).
Use refresh token to get a new token and update refresh token every time you update old token (and when user is logged in, no doubt)
Do not store passwords, credit card numbers and any confidential informations in the token ( I'm shure, you know it :) )
Store all necessary information for checking privileges ( or checking ip, for example ). It is good for REST API and horizontal scaling.